Process for the treatment of blast-furnace slags and other silicate mixtures for the production of cementitious material therefrom.



UNITED sfrA-rns ATENT ossron;

BRUNO BRUHN, or HAMBURG, GERMANY, ASSIGNOR T HENRY EDMUNDS, or LONDON,

' ENGLAND MATERIAL THEREFROM.

Specification of Letters Patent.

Application filed Aprill7,19 05. Serial Ho- 266,116.

To all whom it may concern: 1 Be it known that I, BRUNO Bnunn, a subject of the German Emperor, residing at Hamburg, Germany, have invented a certain new and useful Process for the 5 Treatment of Blast-Furnace Slags and other Silicate Mixtures for the Production of Cementitious Material 'lherefrom, of which the following is a specification.

it is recognized that cementitious silicate mixtures possess quicker and stronger setting properties the more basic they are in characterw The technical literature on this subject shows a'series of experiments and processes involving the addition of basic material, such as lime and other alkaline earth to molten blast furnace slag or other) silicate mixtures in order to obtain a prod uct similar analytically to Portland cementf besides increasing the quantity of lime-a process has also been described for adding such other alkalies as were considered necessary. I v

The present invention differs from the above processes in the fact that a small quantity, such as a few percent, of alkali or alkaline salts are added to the molten silicate mixtures after they have been melted as an easy method of securing the hydraulic setting properties without the addition of other ingredients, such as lime, and so forth. This process is especiall adapted for producing cementitious material fromfidast furnace slag in connection with air granulating processes.

Blast furnace and similar slags melted at high ten1- 3Q peraturcs usually contain only very small quantities of alkalies on account of their volatility. In the case of water granulated slags the addition of alkalics is of little advantage, since they are. easily dissolved and carried away because of their solubility in water, but when the slag is cooled quickly in a dry or semi-dry condition, such dissolving or removal can not take place. The chemical effect of the addition of alkaline material to cold water granulated slag is also different from such addition made when slag is at such a tom- 40 perature that the alkalies or alkaline earths arc entirely 'or partially dissolved with or without chemical reaction or decomposition. The greater intensity of action in the latter case may possibly be explained on different theories. in the first place, the chemical transformation due to the formation of silicates with .quick setting properties, such as alkaline silicates, is probably important and also, in the second place, the alkaline reaction of the water added produces quick sotting propertics. If merely a solution of the alkaline 5O additions takes place in the silicate mixtures the liner distribution through such mixtures perhaps causes a more powerful effect of the alkaline addition acting as a catalytic agent. An exact explanation is not possible on account of the complicated conditions attending the l AGS AND OTHER SlLlCATE MlXTURES FOR THE Patented July 2, 1907.

reciprocal action of the various chemical components and the insuflicient knowledge thereof. The carrying device into which the slags are poured before they are subjected to further treatment for the purpose of oxidation granulation and cooling in any of the various well known processes.

Without being limited to the details of the disclosure in this case, what is claimed as new and what is desired to be secured by LettersPatent is pended claims.

set forth' in the ap- 1. '.llle process for the trealmcnt of blast furnace slag which consists in adding and incorporating a few percent of alkaline salts in molten furnace slag and in oxidizing, granulntlng und cooling the mlxtur e so as to produce highly (:emeniltious mun-rial therefrom without the addl' tion of other ingredients.

of alkaline salts with mollon furnace slag material and in grunulating and cooling; the mixture in the presence of oxygen bcnring: llllid so as to form material therefrom' without grcdicnts.

furnace slag alkaline s:

s for thc treutmcnt of blast furnace slag in adding; and incorporating with molten is lo the extent of not more than highly ccmentltlous the addition of other in a l'ew percent and in treating; and cooling the mixture so us to form highly ccmcnlillous material thercfrimi con mining considcrably loss limo thnnlortlund cement without tho necessity of adding; other ingredients.

for lhc treatment of blast furnace slug which consists in adding and incorporating with highly llculcd slug mntcriul nlkulino salts to the extent of not more than a low pcrcont and in ri'unulutin; and cooling the mixture in thc prcscucc of oxygen bearing fluid so us to produce ccincnlllious mulcriul thcrot'rom.

5. 'lheproccss for he trcnlmcnt of furnace slug; which consists in adding and incorporating a few percent of alkaline salts with highly healed lurnaco slug mntcriul and in grnnulntlng and cooling; the mixture so as to produce highly ccmcniltlous nnitcrial ihcl'cfrom containing considerably less lime than l'orl'lund ncccssily of adding other Ingredients.

(i. The process for the trcutmont of furnace slug which cement Without the consists iii adding; and incorporating a few percent oi alkaline splts with highly heated furnncc slug material and in treating and cooling the mixture so as to produce highly cementitious mulcrial therefrom containing considcrably less lime than Portland cement.

7. The process for the treatment of silicate material which consists in adding and incorporallng wilh highly heated silicate, mutcl'inl alkaline salts to the extent of not more than n no pcl'ccut und in cooling the some so produce. ccmcntltlour. material therefrom, conlalniiu,

as I

sidcrably lcssdlinc than Portland cement.

In testimony whereof, I have signcd my name to this specification in.iho presence of two subscribing witnesses. 

